Means for cooling dynamo-electric machines.



PATENTED MAY 12, 1903.

E.'D. PRIEST. MEANS FOR COOLING DYNAMO ELECTRIC MACHINES.

APPLIOATION FI LED JAN. 18, 1902.

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No. 727,686. I PATENTED MAY 12, 1903.

- E. D. PRIEST-. MEANS FOR COOLING DYNAMO ELEGTRIGMAGHI'NES.

APPLICATION FILED JAN. 18', 1992. I0 MODEL. 4 SHEETS-SHBBT 2.

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Inventor,

Ed yvar-d D Pricstz.

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"PATENTED MAY 12, 1903.

No. 727,686. I

I E. D. PRIEST.

MEANS FOR COOLING DYNAMO ELEOTRICMAGHINES.

APPLICATION FILED JAN. 18, 1902.

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No. 727,686. PATENTED MAY 12, 1903,

' I E. D. PRIEST.

MEANS FOR COOLING DYNAMO ELECTRIC MACHINES.

APPLI'JATION FILED JAN. 18, 1902.

4 SHEBTS-SHEET 4.

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UNITED STATES Patented May 1 2, 1903.

PATENT OFFICE.

EDWARD D. PRIEST, OF SCHENECTADY, NEW YORK, ASSIONOR TO GENERAL ELECTRIC COMPANY, A CORPORATION OF NEW YORK.

MEANS FOR COOLING DYNAMO-ELECTRIC MACHINES.

SEEGIFICATIQN forming part of Letters Patent No. 727,686, dated May 12, 1903.

Application filed January-l8, 1902. Serial No. 90,265. (No model.)

To all w7wmit may concern: Be it known that I, EDWARD D. PRIEST, a citizen of the United States, residing at Schenectady, county of Schenectady, State of New York, have invented certain new and useful Improvements in Means for Cooling Dynamo Electric Machines, of which the following is a specification.

In order to keep the temperature of dy- 1o nauio-electric machines within certain prescribed limits, it is customary to provide them with casings having openings through which a forced circulation of air is passed. This may either be due tothe rotation of the mov- [5 ing element itself or to fan-blades attached thereto. In the former case the action is not entirelysatisfactory forcertain classes of work when used with the dynamo-electric machine as ordinarily constructed. This is due prin- 2o cipally to the poor and ineflicient distribution of the air-currents within the casing. In the latter instance the fan-blades take up valuable space and also require considerable power to drive them. The matterof space is a most important consideration, particularly in connection with motors used on railway-trucks, where the available space is limited and all parts are necessarily made very compact.

My invention has for its object to overcome 0 the difficulties set forth above and to utilize the revolving element of the machine in a manner to produce air-currents of a character suitable to cool the various parts which go to make up a dynamo-electric machine, and 5 this in a simple and efficient manner.

The scope of my invention will be more fully set forth and claimed hereinafter.

In the accompanying drawings, which illustrate an embodiment of my invention, Figure 1 is a view of the commutator end of a railway-motor mounted on an axle. Fig. 2 is a front elevation of the same. Fig. 3 is a longitudinal section of the motor, taken on the line of the armature-shaft. Fig. 4 is a crosssection taken on lines 4 of Fig. 3 looking in the direction of the arrow. Fig. 5 is a crosssection of the gear-end armature-head, taken on line 5 5, with the coils removed and looking in the direction of the arrow. Fig. 6 is a cross-section of the commutator-end armature-head, taken on line 6 6 and looking in the direction of the arrow, the armature-coils being removed. Fig. 7 is a view in elevation of a space-block. Fig. 8 is a sectional view of the space-block, taken on line 8 8 of Fig. 7. Fig. 9 is a view in elevation of one of the spacing-rings or washers. Fig. 10 is a section taken on line 10 10 of Fig. 9. Fig. 11 is a sectionalview of a slight modification, and Fig. 12 is' a detail view showing means for taking air at a point above the machine.

I n carrying out my invention I bore out the shaft carrying the rotating member and connect the opening thus formed with the exterior of the machine-casing through a device which admits air freely, but prevents the entrance of dirt and lubricant. The core of the revolving member is provided with airpassages and is divided into sections by suitable space-blocks having channels or openings which communicate with the opening in the armature-shaft. The heads which hold the laminae in place and form supports for the overhanging ends of the winding, when an overhanging winding is used, are also provided with passages which communicate with the shaft-opening and also with the passages formed in the core. The air-currents created by the rotation of the revolving member in passing through these passages 'cool the adjacent parts and also the winding, after which they are discharged into the interior of the machine-casing and there serve to cool the other windings and the surrounding metal parts. The casing incloses the armature and field-coils in the usual manner and is provided with several openings, one or more of which may be covered, if desired, it being understood, however, that in order to create a forced circulation at least one opening must be uncovered besides the inlet.

My invention is shown as applied to a railway-motor, asit has great utilityin that connection; but it is not to be construed as being limited thereto, for it'is broad enough to include all types of dynamo-electric machines wherein revolving and stationary members or elements are present.

Referring more particularly to Figs. 1 and 2, I have shown a railway-motor the casing of which forms substantially a cube with wellronnded corners. The casing is sleeved on a wheeled axle at 1 in the usual manner and is provided with nose-supports 2 and 3, Whereby the front end of the motor may be springsupported from the trucks. The armatureshaft is connected to the axle through suitable gearing, the latter being inclosed in a casing 4:. The field-magnets are inclosed in a casing 5, the latter being provided in the present instance with six openings, each of which is furnished with a cover W. In the present instance three of these openingsnamely, the one over the commutator and the two in frontare shown as closed with covers; but this number may be varied to suit the climatic conditions or the character of the road-bed. When the motoris used on an elevated structure away from dirt and water, it is evident that more of the openings can be left uncovered than Where the motors are used on a track having the usual road-bed.

Referring to Fig. 3, A represents the armature-shaft, having a central bore or opening J, which extends substantially the entire length of the motor. This opening is in communication with the external air through a specially-formed chute O, that is bolted at P to the side of the motor-casing. Boring out the shaft, in addition to makinga flue or passage for air-currents, decreases the weight of the shaft, and this is important, particularly where the weight of the machine must be limited. The chute O is provided with means for preventing the entrance of lubricant into the interior of the shaft, as will appear hereinafter. The shaft is supported at the ends in suitable bearings, the latter being mounted in heads Q, which inclose the ends of the casing, the openings closed by the heads be ing of such diameters that the armature can be movedlongitudinally through them when it is desired to repair the machine.

Formed on the armature-shaft near the right-hand or gear end are a collar and aslight enlargement, which together form a seat for the head H. The armature-lamina may be ofanysuitable character, providing that when assembled on the shaft air-passages D will be formed that will extend from one head to the other. I have found that three of these passages will afford sufficient carrying capacity for the air-current and will keep the temperature of the core down; but the number and arrangement may be varied to suit the requirements. The lamina: are divided into groups or sections by the space-blocks B. These blocks may be of any suitable character, providing air passages or ducts are made therein which communicate with the longitudinal passages orducts D. In the present instance they are of the character illustrated in 7 and 8 and comprise a main-body punching having openings E, which register with the passages D in the laminae. They are arranged to he slipped on the shaft endwise and are prevented from rotating by the same key which holds the laminae. Extending radially from the main body are a plurality of raises tance apart, at the same time forming air passages or ducts that communicate with the passages D. In other words, a central passage J is provided, and extending parallel therewith and in direct communication are passages D, the latter opening into a plurality of radial passages extending at right angles to the armature-shaft passage J and the passages D. The hub of each space-block being thin, it is necessary to provide means for reinforcing it. This is accomplished by means of the washers or spacingrings F. (Best shown in Figs. 9 and 10.)

Afterthe requisite number of sections of laminae have been assembled on the shaft they are clamped in place by the head L, the latter being retained in place by a nut on the shaft. This head comprises a circular plate G, which engages with and holds the laminte. It is reinforced by a plurality of radial ribs Yand a cylindrical rib G, Figs. 3 and 6. The radial ribs are united bya web G which extends substantially at right angles to the shaft. The web, in addition to acting as a support for the ribs, forms a circular partition,which directs the air-currents outwardly through the windings. The cylindrical rib G, in addition to strengthening the head, also serves to baffle the air-currents as they radiate from the openings II in the shaft and causes a certain portion of them to pass into the ducts D. It is preferable to make these passages somewhat tortuous, so as to derive the greatest cooling effects from the air-currents. The periphery of thehead L is turned true and forms a support for the overhanging ends of the armature-Winding.

Mounted on the left-hand end of the armature-shaft is a commutator 6, composed of a plurality of insulated segments N, which are connected to the conductors K of the armature winding by solder or other suitable means.

The right-hand or gear-end head is provided with a circular plate that engages with the laminae and forms an abutment therefor. Extending radially from the hub and formed integral therewith and with the circular plate is a plu rality of radial ribs U. Extending from a point intermediate the ends of the ribs to the cylindrical flange or oil-thrower X is a conical wall U, which closes inthe end of the armature and presents a smooth unbroken surface, so as to reduce the resistance to the passage of aircurrents. The space between the ribs is in communication with the passages D in the armature-core and also with the interior of the machinecasing. Communication between the ribspaces below and above the conical wall U is established by a plurality of openings U Figs. 3 and 5, and additional baffling means may be provided in the shape of a cylindrical flange U This flange may be omitted, if desired. The outer ends of the radial ribs U are connected to a cylindrical support for the overhanging ends of the armature-winding. This support merges into the oil-thrower or flange X, the latter being made with a deep groove, so as to decrease the liability of lubricant working into the armature-Winding. The flange X is preferably located in such manner that oil will be thrown against the casing instead of against the field-spools and wire mounted thereon.

The gear-end head Q is provided with a bearing which projects under the conical wallU,and between the bearing and the head M is an oil-thrower T, comprising a series of rings which project into corresponding grooves in the head Q and prevent lubricant from working into the air -passages. The grooves in the head communicate with the downwardly-extending passage Q, which in turn opens into the receptacle Q formed in the head.

Secured to the stationary head and preferably formed integral therewith are a number of radially-extending ribs V, Figs. 3 and 4., for preventing rotation of entering air-currents. The object in making the ribs integral with the head is to decrease the cost of construction and to avoid the use of bolts, which are liable to work loose, due to the jarring of the parts. The number of the ribs may be varied as desired. I have found seven to work very satisfactorily and prevent the incoming air-currents from the upper and lower openings from rotating with the revolv ing member instead of being drawn into the ventilating-passages. Referring to Fig. 4, the lining for the bearing and a portion of the head are cut away at Q to receive cottonwaste saturated in grease for lubricating purposes.

The ventilating construction described for the gear end of the armature works very satisfactorily. In making tests with smoke to determine the action of the air-currents within the machine I have discovered that at times there is a tendency for the air to create local circuitsfor example, the air-currents passing out radially at the space-blocks mingle with the incoming currents of air from the uncovered openings in the casing and are thus used over and over again. This action is not particularly marked, but it does exist to a certain degree, and where it is necessary to take advantage of every possible means to keep down the temperature of the machine I providea stationary partition 10. The latter is preferably cast integral with the casing, so as to avoid joints and the use of parts which may become loose. This partition (best shown in Figs. 3 and 4) is provided with a central opening to receive the armature,

the opening being of such size and the partition so placed that it is arranged to receive the flange X on the revolving member and closely embrace it. By reason of this construction the armature is free to move longitudinally within the limits set for it by the thrust-collar or enlargement on the shaft without interfering in any way with the action of the ventilating apparatus. This partition effectively prevents the local air circulation previously referred to.

Referring now to Figs. 3 and 4, the casing is provided with pole-pads 7, to which the laminated detachable pole-pieces 8 are secured. Four of these poles are shown and each is provided with a field-coil 9; but the number and arrangement of the poles may be Varied to suit the requirements.

When the top and bottom covers W on the gear end of the machine are removed, air will pass into the interior of the revolving element, as is indicated by the arrows in Fig. 3. I have also found where openings of considerable area are provided that air-currents will under certain conditions pass into the opening at one point, while certain of the discharged air-currents will pass out of the same opening at another point. In Fig. 3 the arrows indicate the air'eurrents entering the armature-passages through the upper as well as the lower opening. Of course the action of the air-currents in the machine is more or less afiected by the number of openings left uncovered and the arrangement of said openings. By properly arranging the uncovered openings with respect to each other the degree of ventilation can be varied within wide limits. The major portion of the air-currents in the present instance are discharged through the opening under the commutator.

Referring now to Figs. 1 and 3, O represents an air-admitting chute which is secured to the casing by bolts P. Air entering this chute passes into the armature-shaft, thence through the armature. In order to prevent the entrance of lubricant into the air-passages, where it would have a tendency to clog them and also to prevent it from passing into the windings, special means are provided. The lubricant works outward to the end of the shaft and is discharged by the oil-throwers S into a surrounding receptacle formed in the back of the chute 0. Situated below .theshaft is a plate R, having a number of ribs which project between similar ribs formed on the back of the chute 0. These ribs are so positioned with respect to each other that considerable resistance as compared to that of the chute is offered to the entrance of air, while the lubricant is free ,to pass slowly downward into the receptacle formed on the lower part of the casinghead. In other words, two air-admitting openings are provided; but one offers so much more resistance to the passage of air than the other that,-

practically speaking, all of the air is taken in at the mouth of the chute.

I have found that there is a tendency for the lubricating material to be squeezed out between the shaft and the lining for the bearing. At times this has considerable pressure. Hence it becomes necessary to provide special means for preventing it from mingling with the incoming air-currents. This is accomplished by reducing the size of the shaft at the point where the oil-throwing rings S are formed and fitting the plate R closely around said rings. This brings the barrier or portion Z of the plate directly in front of the line of separation of the shaft and lining, so that any lubricant which is projected outward from the bearing at this point will be caught by the plate and permitted to flow downward into the receptacle on the lower portion of the casing-head.

With the air-admitting openings at the gear end arranged as described, there is more or less friction between the entering air-currents and the conical surface of the head. In order to reduce this to a minimum, a stationary wall V, Fig. 11, is interposed between the revolving armature-head and the incoming air-currents. In the present instance this wall takes the form of a cone and is connected to all of the radial ribs V. Air is admitted to the passages between the ribs through openings formed in the heads Q. If the machine is used where considerable dust and dirt are found, the openings in the heads may be provided with chutes of the general character previously described. When arranged as described,a plurality of independent air-admitting passages are provided, which passages radiate from a common point. The center line of each passage is inclined at an angle with respect to the armature-shaft, thus forming a plurality of diverging air-admitting openings.

In Fig. 12 is shown an arrangement for use where the machine is subjected to dust and dirt. It consists of a pipe W, which is secured to a coverW and extends to some point remote from the machine. When the machine is used in a building, it can with advantage extend to the outside. In event of a railway-motor used on surface roads or where there is considerable dust and dirt the pipe is preferably made of canvas or some similar flexible material and extended upward into the car-body. The opening into the pipe may be located under the seats and screened or not, as desired.

What I claim as new, and desire to secure by Letters Patent of the United States, is-

1. A rotary member for a dynamo-electric machine, comprising a hollow shaft, a core mounted thereon, radial spacing devices in the core which form air-passages communicating with the hollow shaft, and which serve to draw air through the hollow shaft, heads for clamping the core in place, and passages in the head which communicate with the opening in the shaft.

2. In an electric machine, the combination of a rotary member comprising a core and its support, conductors which are mounted on the core and overhang at one end, ventilating-passages formed in the core, and a support for the ends of the conductors which also serves as a shield to direct currents of air upon the heated parts.

3. In an electric machine, the combination of a rotary member formed with ventilatingpassages, oil-throwers for preventing access of lubricant to the passages, and baffle-plates upon which the rings throw the oil, the said plates being arranged to prevent the air-currents from carrying lubricant into the ventiiating-passages.

4. In adynamo-electric machine, a rotating member comprising a laminated core and conductors extending beyond the ends of said core, said rotary member being formed with ventilating-passages, a member having an unbroken clamping-surface for engaging the core, and a rib or projection for supporting the ends of the conductors, said last-mentioned member being formed with a ventilating-space communicating with the ventilating-passages referred to, and opening beneath the projecting ends of the conductors.

5. In an electric machine, the combination of a rotary member having communicating longitudinal and radial air-passages, conductors which extend beyond the ends of the core, a support for the ends thereof having air-passages,and an oil-throwing ring secured to the support for preventing the lubricant from working in between the conductors.

6. In an electric machine, the combination with the rotary member having communicating longitudinal and radial air-passages, of a stationary plate arranged adjacent to the entrance of the longitudinal passages to prevent revolution of air-currents.

7. In an electric machine, the combination with the rotary member having ventilatingpassages, of a barrier interposed between the bearing of said member and the entrance to said passages, to prevent the lubricant from the bearing from passing into the entrance with the air-currents.

8. In an electric machine, the combination of a rotary member having longitudinal airpassages, a head for supporting the laminate of the rotary member, conductors supported by the laminae and the head, an oil-receptacle carried by the head, an oil-throwing ring mounted on the shaft of the rotary member, and air-passages which are formed between the receptacle and the oil-throwing ring and are in communication with the said longitudinal passages.

9. In a dynamo-electric machine, the combination of a casing, a revolving member mounted therein and comprising a laminated core having longitudinal and radial air-passages, heads for clamping the laminae together which are provided with radial pasbination of a casing, an armature having a revolving conical head, a hearing which extends under the head, and a plurality of radially-extending ribs which also extend under the head for preventing the air-current within the casing from revolving with the armature.

ll. In a dynamo-electric machine, the combination of a casing having closed ends and an air-admitting opening, a rotary member which is provided with air-carrying passages, and a stationary partition within the casing nvhich closely embraces the revolving member and prevents the creation of local air-currents in the casing.

12. In a dynamo-electric machine, the combination of a casing having an air-admitting opening, an armature revolving therein having an air-carrying passage, a partition which closely embraces one end of the armature for preventing local air-currents, and means for preventing the creation of rotary air-currents as the air enters the casing.

13. In a dynamo-electric machine, the combination of a casing, a revolving member mounted therein, and a head for said member which is provided with radial air-passages and a cylindrical flange the latter acting to baffle the passage of air through the passages.

14. In a core-head, the combination of a hub, a flange which engages with the laminae, a second flange which extends substantially at right angles to the armature shaft and closes in one end of the head, ribs for con necting the two flanges, and a means for baffling air-currents as they pass through the head.

15. In a dynamo-electric machine, the combination of a casing, a revolving member mounted on a hollow shaft, and a chute for admitting air to the interior of the shaft which is provided with two openings, one of which offers a much greater resistance to the passage of air-currents than the other.

16. In a dynamo-electric machine, the combination of a stationary element having a winding, a revolving element also having a winding, a head assisting to support the second winding and an oil-throwing ring secured to the head and located beyond the first-mentioned winding, thereby preventing oil from being deposited on said winding.

17. In a dynamo-electric machine, the combination of a revolving element, a head therefor having an undercut surface, an inclosing casing, and an air-carrying flue or passage which projects beyond the outer edge of the undercut surface for admitting air to the revolving element near its center.

18. In a dynamo-electric machine, the combination of a revolving element, a head therefor having an undercut surface, a casing, a second head having a projection which conforms to the shape of thefirst head, and pas-' 

